1. Field of the Invention
This invention relates to an improved bonding structure and process for attaching a tape providing conductive leads to a semiconductor die having a plurality of mating contact bumps for the conductive leads. More particularly, it relates to such a structure and process which provides a stronger bond between the conductive leads and the mating contact bumps.
2. Description of the Prior Art
Tape automated bonding of semiconductor die is widely practiced in the semiconductor industry at the present time. The tape automated bonding technique is the process of choice for attaching conductive leads to contacts of high volume semiconductor parts. Representative examples of tape automated bonding structures and processes are disclosed in commonly assigned U.S. Pat. No. 4,000,842, issued Jan. 4, 1977 to Burns, in commonly assigned pending Application Serial No. 597,805, filed Apr. 5, 1984 in the name of Carmen D. Burns and entitled "Controlled Collapse Thermocompression Gang Bonding", application Ser. No. 628,106, filed July 5, 1984, in the name of Thanomsak Sankhagowit and entitled "Pretestable Semiconductor Die Package and Fabrication Method," application Ser. No. 878,930, filed June 26, 1986 in the names of Ali Emamjomeh and Richard Rice and entitled "Hinge Tape" and in U.S. Pat. No. 4,234,666. As practiced in the prior art, a bumped metallic tape has been used with semiconductor die having flat, thin bonding pads, in order to space the conductive leads above the semiconductor die surface. Conversely, when the semiconductor die has bumped contacts to space the conductive leads above the semiconductor die surface, a flat metallic tape has been used. While the tape automated bonding structure and process has been highly successful in practice, any modification that would improve results obtained with tape automated bonding would be desirable. In particular, it would be helpful to increase the bonding strength obtained with tape automated bonding and to provide a tape automated bonding structure that is not susceptible to shorting by drooping when heated to elevated temperatures in subsequent processing.